1. Field of the Invention
The invention relates to a refractory product according to ISO/R 836, DIN 51060, in the form of an unmolded or molded batch, which in situ is highly resistant to the corrosion by fayalitic slags (iron silicate slags) and sulfates and is resistant to molten heavy nonferrous metals, especially to copper melts. In addition, the invention relates in particular to uses of the batch.
2. Description of the Related Art
Fayalitic slags are formed, for example, during the manufacture of copper from copper pyrite (CuFeS2). Copper pyrite is roasted to produce so-called copper matte containing cuprous sulfide (Cu2S) and iron compounds, e.g. FeS and Fe2O3. The copper matte is further processed to raw copper, in the course of which molten copper matte is treated with supply of air and addition of SiO2, e.g. in the form of quartz, in a converter. In the process, a fayalitic slag is formed, containing mainly the mineral fayalite (2FeO.SiO2) and raw cuprous oxide (Cu2O).
At present, the converters for the manufacture of raw copper, e.g. a Pierce-Smith converter, are lined on the firing side mainly with fired magnesia-chromite products (e.g. DE 1471231 A1). However, these refractory products have only insufficient resistance to the corrosion by sulfates, which result from the oxidation of the sulfides, for example in the form of magnesium sulfate. Moreover, magnesia-chromite bricks have only limited or inadequate high-temperature anti-wetting properties, and they have inadequate resistance to penetration by hot heavy nonferrous metals, especially copper melts.
Magnesia-chromite bricks are also used in melting systems for the production of other nonferrous metals (heavy nonferrous metals such as Ni, Pb, Sn, Zn) and suffer from problems of similar nature there.